This invention relates to video conferencing, and more particularly, to correcting for eye-gaze between each viewer and the corresponding image or images of persons being viewed.
A primary concern in video-teleconferencing is a lack of eye contact between conferees. Eye contact is not possible with common terminal configurations, because a camera is placed at the perimeter of the display that images a distant conferee, so that the camera does not interfere with a local conferee""s viewing of the display. In a typical desktop video-teleconferencing setup, a camera and the display screen cannot be physically aligned. In other words, in order for the participant to make eye contact with the camera, the user must shift his eyes from the display terminal and look upward towards the camera. But, in order for the participant to see who he is viewing, he must look straight at the display terminal and not directly into the camera.
As a result, when the participant looks directly at the display terminal, images of the user received by the camera appear to show that the participant is looking down with a peculiar eye-gaze. With this configuration the conferees fail to look directly into the camera, which results in the appearance that the conferees are looking away or down and appear disinterested in the conversation. Accordingly, there is no direct eye-to-eye contact between participants of the typical desktop video-teleconferencing setup video conferencing system.
One solution for this eye-gaze phenomenon is for the participants to sit further away from their display screens. Research has shown that if the divergence angle between the camera on the top of a 21-inch monitor and the normal viewing position is approximately 20 inches away from the screen, the divergence angle will be 17 degrees, well above the threshold (5 degrees) at which eye-contact can be maintained. Sitting far enough away from the screen (several feet) to meet the threshold, however, ruins much of the communication value of video communication system and becomes almost as ineffective as speaking to someone on a telephone.
Several systems have been proposed to reduce or eliminate the angular deviation using special hardware. One commonly used hardware component to correct for eye-gaze in video conferencing is to use a beam-splitter. A beam-splitter is a semi-reflective transparent panel sometimes called a one way mirror, half-silvered mirror or a semi-silvered mirror. The problem with this and other similar hardware solutions is that they are very expensive and require bulky setup.
Other numerous solutions to create eye-contact have been attempted through the use of computer vision and computer graphics algorithms. Most of these proposed solutions suffer from poor image capture quality, poor image display quality, and excessive expense in terms of computation and memory resources.
A system and method for correcting eye-gaze in video teleconferencing systems is described. In one implementation, first and second video images representative of a first conferee taken from different views are concurrently captured. A head position of the first conferee is tracked from the first and second video images. Matching features and contours from the first and second video images are ascertained. The head position as well as the matching features and contours from the first and second video images are synthesized to generate a virtual image video stream of the first conferee that makes the first conferee appear to be making eye contact with a second conferee who is watching the virtual image video stream.
The following implementations, therefore, introduce the broad concept of correcting for eye-gaze by blending information captured from a stereoscopic view of the conferee and generating a virtual image video stream of the conferee. A personalized face model of the conferee is used to track head position of the conferee.